000
FXUS61 KPHI 301946
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
346 PM EDT THU JUL 30 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH OUR REGION TONIGHT, THEN STALL
TO OUR SOUTH AND EAST ON FRIDAY. THE NEXT WEAK COLD FRONT SHOULD
CROSS OUR AREA LATE SATURDAY, BEFORE STALLING OFFSHORE SUNDAY. A
FEW WEAK WAVES OF LOW PRESSURE MAY TRACK ALONG THIS FRONT MONDAY,
WHILE HIGH PRESSURE MOVES IN FROM THE WEST. A STRONGER COLD FRONT
IS EXPECTED TO ARRIVE TUESDAY, THEN STALL NEARBY WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE LINE OF SHOWERS AND THUNDERSTORMS HAD REACHED THE INTERSTATE 95
CORRIDOR IN OUR REGION AT 330 PM. IT WILL CONTINUE TO MOVE EASTWARD
AND IT WILL PASS OFF THE COAST DURING THE EARLY EVENING HOURS.
SCATTERED LIGHT RAIN SHOWERS WILL LIKELY LINGER FOR AN HOUR OR TWO
AFTER THE MAIN LINE OF PRECIPITATION PASSES.
THE ARRIVAL OF THE SHOWERS AND THUNDERSTORMS RESULTED IN A DROP IN
TEMPERATURES. AS A RESULT, WE HAVE CANCELLED THE EXCESSIVE HEATWARNING.
THE FRONTAL BOUNDARY WAS TRAILING THE PRECIPITATION. IT WAS LOCATED
ACROSS CENTRAL NEW YORK, CENTRAL PENNSYLVANIA AND EASTERN WEST
VIRGINIA AT MID AFTERNOON. THE BOUNDARY IS FORECAST TO PASS THROUGH
OUR REGION OVERNIGHT, BETWEEN ABOUT 1000 PM AND 200 AM.
CLEARING IS EXPECTED FOR TONIGHT. TEMPERATURES ARE FORECAST TO DROP
INTO THE 60S AT MOST LOCATIONS WITH A SOUTHWEST WIND SHIFTING TO THE
NORTHWEST. WIND SPEEDS SHOULD BE 10 MPH OR LESS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
DRY AIR WILL BUILD INTO OUR REGION FROM THE NORTHWEST AND WEST FOR
FRIDAY. DEW POINT READINGS ARE ANTICIPATED TO DROP INTO THE 50S AT
MOST LOCATIONS, SO IT WILL BE NOTICEABLY LESS HUMID THAN TODAY. EVEN
WITH THE PASSAGE OF THE FRONT, CONDITIONS WILL BE QUITE WARM ON
FRIDAY. MAXIMUM TEMPERATURES WILL BE AROUND 90 DEGREES EXCEPT IN THE
ELEVATED TERRAIN. A NORTHWEST TO WEST WIND AT 6 TO 12 MPH IS
ANTICIPATED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
OVERVIEW...
A CLOSED MID-LEVEL LOW OVER HUDSON`S BAY WILL MAINTAIN A TROUGH
IN THE EAST CONUS AND A GENERAL CYCLONIC FLOW ALOFT THROUGH THE
PERIOD. THERE IS SOME MODEL DISAGREEMENT REGARDING S/WV ENERGY
ENTERING THE GREAT LAKES REGION ON SUNDAY...AND TO WHAT EXTENT
THE TROUGH AMPLIFIES AS A RESULT. THERE HAS BEEN LITTLE RUN-TO-
RUN OPERATIONAL MODEL CONSISTENCY IN THIS REGARD...THUS RELIED
ON THE GEFS/ECENS ENSEMBLE MEANS. THE MAIN IMPLICATION IS WITH
REGARD TO THE PLACEMENT OF AN OFFSHORE FRONT ON MON-TUE AND THE
TIMING OF A ANOTHER COLD FROPA ON TUE-WED.
A WEAK COLD FRONTAL PASSAGE IS EXPECTED ON SATURDAY NIGHT...W/
THE BEST CHC FOR SHRA/TSRA NW OF I-95. THIS FRONT WILL STALL
JUST OFFSHORE THRU TUE AND MAY EVEN WASH OUT. AS AFORMENTIONED
S/WV ENERGY ENTERS THE EAST CONUSTROUGH... THIS WILL TURN THE
FLOW MORE MERIDIONAL...W/ TROPICAL MOISTURE MOVING N. THE BULK
OF THIS MOISTURE SHOULD REMAIN OFFSHORE.
THE NEXT CHC OF SHRA/TSRA WILL BE WITH ANOTHER COLD FROPA
CURRENTLY TIMED IN THE LATE TUE/EARLY WED PERIOD. OVERALL...
EARLY TRENDS /D+5 TO D+7/ INDICATE THIS FRONT WILL STALL NEAR
THE NJ COAST AND WASH OUT. THERE ARE NO INDICATIONS OF A BIG
CHANGE IN THE SYNOPTIC PATTERN THRU D+7...SO THIS SOLUTION IS
PLAUSIBLE...ESPECIALLY IF THE MID-LEVEL FLOW PARALLELS THE
FRONT AS CURRENTLY INDICATED. ABOVE NORMAL TEMPERATURES
EXPECTED THRU THE PERIOD.
DALIES...
SATURDAY...THUNDERSTORMS ARE POSSIBLE OVER THE LEHIGH VALLEY AND
POCONOS LATE SATAFTN/EARLY EVE...BUT MOISTURE MAY BE LIMITED...
SO COVERAGE IS QUESTIONABLE AS WELL AS HOW FAR SOUTH/EAST THESE
STORMS PROGRESS. AN APPROACHING S/WVTROUGH WILL LEAD TO STEEP
MID-LEVEL LAPSE RATES...WHILE A WEAK COLD FRONT POOLS LOW LEVEL
MOISTURE...AND PROVIDES A SOURCE OF LIFT. ML CAPE IS MODELED
AROUND 1 KJ...WHILE BULK SHEAR APPROACHES 40 KNOTS. BOTH OF THESE
FACTORS ARE MOST FAVORABLE OVER THE LEHIGH VALLEY AND POCONOS.
THERE IS THE POTENTIAL FOR GUSTY WINDS...WITH MODEL SOUNDINGS
EXHIBITING AN INVERTED-V PROFILE NEAR THE SURFACE...AS WELL AS
A HEALTHY D-CAPE APPROACHING 1.4 KJ. SMALL HAIL IS ALSO POSSIBLE
...AS WBZ VALUES FALL BLW 10 KFT IN THE AFTN....AS WELL AS H50
TEMPS AROUND -12C. OTHERWISE...A PARTLY TO MOSTLY SUNNY SATURDAY
IS ANTICIPATED.
SUN...S/WV RIDGING ALOFT W/ HIGH PRES BRIEFLY MOVING IN BEHIND
DEPARTING COLD FRONT. THIS WILL PROMOTE A MOSTLY SUNNY AND DRY
DAY. THE GRADIENT MAY RELAX ENOUGH FOR A SEA-BREEZE TO DEVELOP
ALONG PORTIONS OF THE COAST.
MON...SHRA/TSRA ARE POSSIBLE MON AFTN AS S/WVIMPULSE SKIRTS BY
TO THE NORTH AND A LEETROUGH SETS UP WEST OF I-95. MOISTURE IS
LIMITED...AND POPS WERE FOCUSED OVER THE NORTHERN HALF OF THE
CWA...CLOSER TO THE BETTER DYNAMICS. THE BEST CHC OF THUNDER IS
ALSO OVER THIS AREA...W/ MORE FAVORABLE CONVECTIVE PARAMETERS.
THE AFOREMENTIONED PLUME OF TROPICAL MOISTURE BUT MAY BE CLOSE
ENOUGH FOR INCREASED CLOUDINESS NEAR THE COASTLINE ON MONDAY.
TUE THRU THU...THERE REMAINS ABOVE AVERAGE UNCERTAINTY DURING
THIS TIME FRAME. THE BEST CHANCE OF SHRA/TSRA WILL BE W/ THE
COLD FRONTAL PASSAGE LATE TUE/EARLY WED. IF THE FRONT STALLS...
SHRA/TSRA ARE POSSIBLE THRU THU.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
A LINE OF SHOWERS AND THUNDERSTORMS WAS AFFECTING KTTN, KPNE, KPHL
AND KILG AROUND 1930Z. THE LINE WILL CONTINUE TO MOVE EASTWARD AND
IT SHOULD PASS OFF THE COAST EARLY THIS EVENING.
SCATTERED SHOWERS WILL LINGER INTO EARLY THIS EVENING WITH IMPROVING
CONDITIONS.
THE SKY IS EXPECTED TO CLEAR FOR TONIGHT AND FRIDAY. VFR CONDITIONS
ARE ANTICIPATED. HOWEVER, PATCHY LIGHT FOG IS POSSIBLE AROUND KRDG,
KABE AND KMIV LATE TONIGHT AND EARLY ON FRIDAY MORNING.
A SOUTHWEST WIND AROUND 5 TO 10 KNOTS THIS EVENING IS FORECAST TO
SHIFT TO THE NORTHWEST OVERNIGHT. WIND SPEEDS MAY DROP BELOW 5 KNOTS
AT SOME LOCATIONS FOR A TIME OVERNIGHT.
OUTLOOK...
SAT AND SAT NIGHT...MAINLY VFR...WITH MVFR POSSIBLE SAT EVE AND
EARLY SAT NIGHT IN SHRA/TSRA MAINLY CONFINED TO ABE AND TTN.
SUN...VFR CONDITIONS EXPECTED.
MON AND TUE...MAINLY VFR...W/ MVFR POSSIBLE IN SHRA/TSRA...
ESPECIALLY ON TUE.
&&
.MARINE...
A COLD FRONT FROM THE NORTHWEST IS FORECAST TO PASS ACROSS THE
COASTAL WATERS OF NEW JERSEY AND DELAWARE TONIGHT.
A SOUTHWEST WIND AROUND 10 TO 15 KNOTS IS EXPECTED INTO THIS EVENING
WITH GUSTS NEAR 20 KNOTS. LOCALIZED GUSTS NEAR 25 KNOTS ARE POSSIBLE
ON OUR WATERS OFF MONMOUTH COUNTY INTO EARLY THIS EVENING. HOWEVER,
THEY SHOULD NOT BE WIDESPREAD ENOUGH TO WARRANT A SMALL CRAFT
ADVISORY.
THE WIND IS FORECAST TO SHIFT TO THE NORTHWEST FOR LATE TONIGHT AND
FRIDAY MORNING AT SPEEDS OF 10 TO 15 KNOTS. WIND SPEEDS WILL LIKELY
DECREASE ON FRIDAY AFTERNOON AS AIR TEMPERATURES BEGIN TO EXCEED THE
WATER TEMPERATURES AND ATMOSPHERIC MIXING IS REDUCED.
WAVE HEIGHTS ON OUR OCEAN WATERS SHOULD FAVOR THE 2 TO 4 FOOT RANGE.
WAVES ON DELAWARE BAY ARE EXPECTED TO BE 2 FEET OR LESS.
OUTLOOK...
FRIDAY THROUGH TUESDAY...A BRIEF PERIOD OF SCA WINDS AND SEAS ARE
POSSIBLE SAT NIGHT AND SUN MORNING WITH A COLD FRONTAL PASSAGE.
OTHERWISE...SUB-SCA CONDITIONS EXPECTED FOR THE REMAINDER OF THE
PERIOD.
&&
.RIP CURRENTS...
A SOUTHEAST SWELL WITH A WAVE PERIOD OF 8 TO 10 SECONDS WILL
CONTINUE TO RESULT IN A MODERATE RISK FOR THE DEVELOPMENT OF
DANGEROUS RIP CURRENTS ALONG THE COASTS OF NEW JERSEY AND DELAWARE
FOR THE BALANCE OF TODAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...EXCESSIVE HEATWARNING UNTIL 6 PM EDT THIS EVENING FOR PAZ070-
071-102-104-106.
NJ...EXCESSIVE HEATWARNING UNTIL 6 PM EDT THIS EVENING FOR NJZ015-
017>019.
DE...EXCESSIVE HEATWARNING UNTIL 6 PM EDT THIS EVENING FOR DEZ001.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANCK/GORSE
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...FRANCK
AVIATION...FRANCK/IOVINO
MARINE...FRANCK/IOVINO
RIP CURRENTS...IOVINO